1. Field of the Invention
The present invention relates to a rotary compressor in which a rotary sleeve is floatingly suspended in the central housing and a rotor with a vane is rotatably housed within said rotary sleeve. More specifically, the present invention is directed to the floating-suspension mechanism of the rotary sleeve.
2. Description of the Prior Art
Generally speaking, the vane-type rotary compressor is required to have a different performance depending on the intended use. For instance, an auto-engine supercharger is required to withstand high pressure and a wide range of rpms.
For this purpose it is effective to provide between the central housing and the vaned rotor, a rotary sleeve floatingly suspended relative to said central housing through a pneumatic bearing chamber, and to minimize the friction between the vane and the rotary sleeve by making the rotary sleeve rotate together with said rotor. Such an arrangement suppresses heat generation due to the rotational friction of the vane, realizing a non-lubricated rotation and large flow rate in a wide range of rpms.
In this rotary compressor the rotary sleeve, floatingly suspended, must be able to rotate smoothly within the central housing. The rotary sleeve tends to be thermally deformed to a hourglass shape as the result of its inside surface being heated by adiabatic compression of the gas with both of its ends being bent outwardly. To prevent such a deformation it is important to avoid as far as possible, contact of both ends with the central housing. Furthermore, the rotary sleeve is more loaded at its center and less and less loaded toward its ends and therefore both ends of the rotary sleeve should not be allowed to displace and touch the inside surface of the central housing, resulting in a seizure.